170 Bulletin, Vanderbilt Marine Museum, Vol. IV 



first few suckers, but toward the outer end the suckers become very 

 small and the denticles quite sharp. The big suckers are a little 

 oblique, wide and deep, swollen underneath. The marginal suckers 

 are very much smaller, shallower, more oblique, with the entire rim 

 finely denticulate, the denticles on the outer margin of each ring being 

 longer and strongly incurved. Toward the tip immediately beyond the 

 rows of larger suckers there are a little group of sharply denticulated 

 suckers arranged in four rows and resembling the small marginal 

 suckers. These four rows decrease in size rapidly and are supplanted 

 by eight rows of very small suckers with tiny apertures, all crowded 

 closely together and covering the entire surface of the terminal sec- 

 tion to the tip. 



The suckers of the sessile arms are large and approximately equal 

 on the second and third pairs of arms, on which they are nearly equal 

 to those of the tentacular arms; the suckers of the dorsal arms are 

 intermediate in size between those of the lateral and ventral arms; 

 the suckers of the ventral arms being the smallest. Proximally on each 

 arm there are four or five smaller suckers, beyond which the suckers 

 increase rapidly in size, these suckers having the rim margin nearly 

 entire, with only a few blunt teeth on the outer side. Beyond these 

 are about a dozen of the largest size suckers, which are deep, oblique, 

 cup-shaped, somewhat swollen in the middle, with oblique horny rings, 

 entire on the inner margin but on the outer half with a strongly in- 

 curved, acute median tooth ; on either side of which there are four or 

 five short blunt teeth; on the suckers near the base of the arm these 

 teeth are fewer and shorter, but distally they are more numerous, 

 sharper and the entire ring is frequently denticulate. Beyond the 

 large suckers on the outer fourth of the arm there is a regularly de- 

 creasing series of 30 to 40 smaller ones, extending quite to the tip. 

 These smaller suckers graduate in size and shape to the large ones, 

 but have the inner margin usually entire and the outer set with four 

 to five sharp incurved teeth. The small suckers are very oblique and 

 one-sided. The membrane around the margin of the suckers is thick- 

 ened, but especially so on the basal ones. Both "Ara" specimens are 

 females; for description of the hectocotylized arm of the male con- 

 sult Verrill (1872). 



The external buccal membrane is small, much wrinkled on its inner 

 surface, with its border prolonged into seven acute angles, from which 

 membranes extend to the opposite arms. The jaws are very sharp, 

 reddish brown or reddish black, with the posterior borders of the 



